The present invention relates to a positioning method, a positioning device, and a program.
The global positioning system (GPS) is widely known as a satellite positioning system. The GPS is utilized for a positioning device provided in a portable telephone, a car navigation system, and the like. A GPS positioning device calculates its current position by calculating four parameters (i.e., three-dimensional coordinate values that indicate the position of the GPS positioning device and a clock error) based on information such as the positions of a plurality of GPS satellites and the pseudo-range between each GPS satellite and the GPS positioning device (i.e., positioning calculations).
However, since a positioning process that uses satellite signals from positioning satellites involves various error factors such as multipath effects, a positioning error may inevitably occur. Therefore, various technologies that reduce a positioning error have been proposed. For example, JP-A-2001-337156 discloses technology relating to a positioning process using a Kalman filter.
As the positioning process, a positioning process using a least-square method and a positioning process using a Kalman filter as disclosed in JP-A-2001-337156 have been widely known. However, these positioning processes have not been used in combination (i.e., only one of these processes has been generally used).